Cushion for ventilation interface

ABSTRACT

In accordance with at least one exemplary embodiment, a cushion for a ventilation interface is disclosed. A ventilation mask can include a mask body adapted to matingly engage with the cushion. The cushion can be a double-membrane cushion having an outer sealing membrane and an inner membrane, both of which can extend from a frame. The outer sealing membrane can have a face-contacting portion. The inner membrane can be outwardly oriented from the frame.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/266,707, filed Nov. 7, 2008, which claims priority under 35 U.S.C.§119(e), to U.S. Provisional Patent Application No. 60/996,229, filedNov. 7, 2007, the disclosures of which are incorporated by referenceherein in their entireties.

BACKGROUND

Ventilation interfaces requiring a cushion for providing a seal with auser's face are used for various applications. One such applicationinvolves current treatments for obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome (commonly referred to as obstructivesleep apnea, sleep apnea syndrome, and/or sleep apnea) is a medicalcondition that includes repeated, prolonged episodes of cessation ofbreathing during sleep. During a period of wakefulness, the muscles ofthe upper part of the throat passage of an individual keep the passageopen, thereby permitting an adequate amount of oxygen to flow into thelungs. During sleep, the throat passage tends to narrow due to therelaxation of the muscles. In those individuals having a relativelynormal-sized throat passage, the narrowed throat passage remains openenough to permit an adequate amount of oxygen to flow into the lungs.However, in those individuals having a relatively smaller-sized throatpassage, the narrowed throat passage prohibits an adequate amount ofoxygen from flowing into the lungs. Additionally, a nasal obstruction,such as a relatively large tongue, and/or certain shapes of the palateand/or the jaw of the individual, further prohibit an adequate amount ofoxygen from flowing into the lungs.

An individual having the above-discussed conditions can stop breathingfor one or more prolonged periods of time (e.g., ten seconds or more).The prolonged periods of time during which breathing is stopped, orapneas, are generally followed by sudden reflexive attempts to breathe.The reflexive attempts to breathe are generally accompanied by a changefrom a relatively deeper stage of sleep to a relatively lighter stage ofsleep. As a result, the individual suffering from obstructive sleepapnea syndrome generally experiences fragmented sleep that is notrestful. The fragmented sleep results in one or more of excessive and/orinappropriate daytime drowsiness, headache, weight gain or loss, limitedattention span, memory loss, poor judgment, personality changes,lethargy, inability to maintain concentration, and depression.

Other medical conditions can also prevent individuals, including adultsand infants, from receiving an adequate amount of oxygen into the lungs.For example, an infant who is born prematurely can have lungs that arenot developed to an extent necessary to receive an adequate amount ofoxygen. Further, prior to, during and/or subsequent to certain medicalprocedures and/or medical treatments, an individual can be unable toreceive an adequate amount of oxygen.

Under these circumstances, it is known to use a ventilation interface toapply a positive pressure to the throat of the individual, therebypermitting an adequate amount of oxygen to flow into the lungs. In knownventilation interfaces, oxygen and/or room air containing oxygen isdelivered through the mouth and/or nose of the individual.

Existing types of positive pressure applied by the known ventilationinterface include continuous positive airway pressure (CPAP), in which apositive pressure is maintained in the throat passage throughout arespiratory cycle, bi-level positive airway pressure (BiPAP), in which arelatively high positive pressure is maintained during inspiration and arelatively low positive pressure is maintained during expiration, andintermittent mechanical positive pressure ventilation (IPPV) in which apositive pressure is applied when apnea is sensed (I.e., the positiveairway pressure is applied intermittently or non-continuously)

Ventilation interfaces of ventilation systems include nasal masks andfull masks, among others. For example, many nasal ventilation systemsinclude a mask interface that fits over the nose of a user. The mask isintended to provide a space of gas (e.g., air) for inhalation into thelungs for respiration. Such systems frequently suffer from gas leakage,creating an inability to assure ventilation in many users.

For example, some conventional masks incorporate a sealing surface thatextends around the periphery of the mask. The sealing surface is often amolded or formed surface made from a resilient material includingelastomers such as plastics, rubbers and foams. Such masks haveperformed well when the fit is good between the contoured sealingsurface and the corresponding contours of the user's face.

Nevertheless, some users will not have an optimal seal fit and gaps inthe seal-to-face interface do occur. Often this is remedied by applyinggreater force to further compress the sealing surface against a user'sface, thereby attaining a seal in those areas where the gaps occurred.This often produces user discomfort and may produce various types ofskin irritation, particularly where the applied force exceeds the localperfusion pressure (i.e. the pressure that is sufficient to cut offsurface blood flow).

Also, because many conventional ventilation systems use a headgearsystem having straps to bind the mask in place; the system is tightenedto obtain a sufficient seal if one does not exist. The mask, headgearand/or individual straps thereby place greater pressure on the patient'sface and/or head. Thus, discomfort to a patient can occur at placesremote from the sealing surface.

Sealing problems causing discomfort are often exacerbated when thepositive pressure of the gas being supplied is relatively high or iscyclical to high levels. The mask must be held against the face with aforce sufficient to seal against leakage of the peak pressure of thesupplied gas and as the gas pressure increases so does the needed forceto prevent leakage.

Overall, user discomfort must be taken into consideration as it may wellcause discontinued cooperation with the treatment regimen.

Various cushions for ventilation mask are known. For example, numerouspatents teach nasal cushions for nasal masks, such as related U.S. Pat.No. 6,112,746 (Kwok et al.), U.S. Pat. No. 6,357,441 (Kwok et al.) andU.S. Pat. No. 6,634,358 (Kwok et al.), assigned to ResMed, Inc., thedisclosures of which are hereby incorporated by reference in theirentireties.

SUMMARY

According to at least one embodiment, a ventilation mask can include amask body adapted to matingly engage with a cushion. The cushion can bea double-membrane cushion having an outer sealing membrane and an innermembrane, both of which can extend from a frame. The outer sealingmembrane can have a face-contacting portion. The inner membrane can beoutwardly oriented from the frame.

In another exemplary embodiment, a double-membrane nasal cushion for anasal mask can include a frame. Extending from portions of the frame canbe an outer sealing membrane and an inner membrane. The outer sealingmembrane can have a face-contacting portion. The inner membrane can beoutwardly curved.

BRIEF DESCRIPTION OF THE FIGURES

Advantages of embodiments of the present invention will be apparent fromthe following detailed description of the exemplary embodiments thereof,which description should be considered in conjunction with theaccompanying drawings in which:

FIG. 1 is a side perspective view of an exemplary nasal mask.

FIG. 2 is a cross-sectional view of an exemplary cushion taken alongline AA′ of FIG. 1.

FIG. 3 is a cross-sectional view of another exemplary cushion takenalong line AA′ of FIG. 1.

FIG. 4 is a cross-sectional view of a further exemplary cushion takenalong line AA′ of FIG. 1.

FIG. 5 is a side perspective view of an exemplary full mask.

FIG. 6 is a side perspective view of an exemplary hybrid mask.

DETAILED DESCRIPTION

Aspects of the invention are disclosed in the following description andrelated drawings directed to specific embodiments of the invention.Alternate embodiments may be devised without departing from the spiritor the scope of the invention. Additionally, well-known elements ofexemplary embodiments of the invention will not be described in detailor will be omitted so as not to obscure the relevant details of theinvention. Further, to facilitate an understanding of the descriptiondiscussion of several terms used herein follows.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments Likewise, the terms “embodiments ofthe invention”, “embodiment” or “invention” do not require that allembodiments of the invention include the discussed feature, advantage ormode of operation.

Cushion embodiments can be designed to cooperate with nearly anyventilation interface that makes use of a cushion for sealing engagementwith portions of a user's face. For examples, embodiments can bedesigned to cooperate with nasal masks, oral masks, full masks andportions of hybrid masks (i.e. those masks having an oral cavity andeither nasal inserts or nasal prongs) of various styles and shapes aswill be appreciated by those having ordinary skill in the art.

Nevertheless, for illustrative purpose and in a non-limiting fashion, atleast one exemplary embodiment is described herein in reference to nasalmasks, particularly nasal masks having a generally triangular portionadapted to mate (with or without additional mounting components) with anasal cushion having a substantially triangularly-shaped (i.e.three-sided) frame. The nasal cushion can be a double-membrane cushionhaving an outwardly oriented inner membrane.

Referring to FIGS. 1, 5 and 6, nasal ventilation mask 8, 68 and 88 foruse with a ventilation device (e.g., CPAP units, BiPAP units and IPPVunits) is shown. Mask 8, 68 or 88 can include cushion 10, 60 and 90mated to mask shell 12, 72 or 92 through coupling of cushion mating edge4, 61 or 84 and mask mating edge 13, 63, or 93 defined respectivelythereon. For instance, mating edge 4, 61 or 84 can be defined onsubstantially triangularly-shaped frame 1, 61 or 81 of cushion 10, 60 or90. Correspondingly, mating edge 13, 63 or 93 can be a generallytriangular portion of mask shell 12, 72 or 92, which can be generallyperimetrical in nature as related to mask shell 12.

As one non-limiting example, mating edge 4, 61 or 84 and mating edge 13,63 or 93 can be either the female edge or the male edge of atongue-and-groove attachment system. For example, mating edge 4, 61 or84 can be formed to include a grooved edge adapted to received a tongue(ridge) formed on mating edge 13, 63 or 93. Additional mountingcomponents, such as a mounting ring (not shown), can be provided to moresecurely hold mating edge 4, 61 or 84 and mating edge 13, 63 or 93 inmating engagement. Alternatively, a barb (not shown) can be formed inthe grooved edge of mating edge 4, 61 or 84 to provide a more secureengagement. Regardless of the exact mating engagement, cushion 10, 60 or90 can be removably engaged with mask shell 12, 72 or 92 to allow forreplacement.

Alternatively, cushion 10, 60 or 90 can be permanently attached to maskshell 12, 72 or 92 by any means known to one having ordinary skill inthe art. For example, cushion 10, 60 or 90 can be glued to mask shell12, 72 or 92 or cushion 10, 60 or 90 can be integrally formed with maskshell 12, 72 or 92 by any conventional molding process known to onehaving ordinary skill in the art.

With respect to FIGS. 1-6 cushion 10, 40, 50, 60 or 90 can be adouble-membrane cushion having outer sealing membrane 2, 42, 52, 62 or82 and inner membrane 3, 43 or 53. Outer sealing membrane 2, 42, 52, 62or 82 and inner membrane 3, 43 or 53 can both extend from frame 1, 41,51, 61 or 81. Alternatively, outer sealing membrane 2, 42, 52, 62 or 82and inner membrane 3, 43 or 53 can be separate. Either or both of outersealing membrane 2, 42, 52, 62 or 82 and inner membrane 3, 43 or 53 canassemble directly to mask shell 12, 72 or 92 or assemble directly toframe 1, 41, 51, 61 or 81 or any combination thereof. For example, innermembrane 3, 43 or 53 may extend integrally from frame 1, 41, 51, 61 or81 and outer sealing membrane 2, 42, 52, 62 or 82 may be attached tomask shell 12, 72 or 92 or outer sealing membrane 2, 42, 52, 62 or 82may be non-integrally attached to any portion of cushion 10, 40, 50, 60or 90. Further, in at least one exemplary embodiment, more than twomembranes can be present.

Outer sealing membrane 2, 42, 52, 62 or 82 can be thinner and moreflexible than inner membrane 3, 43 or 53. A portion of sealing membrane2, 42, 52, 62 or 82 can be a sealing portion that can be held againstportions of a user's face when in use. For example, the sealing portionof sealing membrane 2, 42, 52, 62 or 82 can make contact with a user'sface, when in use, proximate the bridge of the nose, around the cheeks,and proximate the skin between the upper lip and the base of the nose.Cushion 10 can have indentation 11 formed in a contoured fashion toreceive the bridge of a user's nose.

In at least one exemplary embodiment, inner membrane 3, 43 or 53 canhave notched and cut-out (missing) portions. For example, the nasalbridge region of inner membrane 3 can be removed (cut-out). Such designfeatures are not to be considered outside the scope of an inner membranein accordance with at least one embodiment. As described further below,inner membrane 3, 43 or 53 can be outwardly oriented.

Mask shell 12, 72 or 92 can also include port 14, 74 or 94. Couplingtube 16, 76 or 96 can be provided in fluid communication with mask 8, 68or 88 via port 14, 74 or 94. Coupling tube 16, 76 or 96 can beswivelably attached to mask shell 12, 72 or 92. Coupling tube 16, 76 or96 can be fitted with additional tubing (not shown) leading to aventilation device (not shown) to provide, for example, gas underpositive pressure to a user. Gas can be provided under pressure tocentral passageway 18, 48 or 58 formed within the cavity defined bycushion 10, 40, 50, 60 or 90. Central passageway 18, 48, or 58 can alsofunction as a nose-receiving cavity when in use.

Arm 20 or 70 can extend from mask shell 12 or 72. The arm 20 or 70 canbe assembled to the mask shell 12 or 72 or could be integral with themask shell. Arm 20 or 70 may have a pad (not shown) disposed to providea comfortable association between the arm and the user's forehead.Alternatively, arm 20 or 70 may also have a cross bar 30 or 73, with atleast one pad 32 or 75. The pad 32 or 75 can also be made of a unitarypiece of flexible material, for example silicone elastomer, foam, gel,and other like materials. The arm 20 or 70, crossbar 30 or 73, and pad32 or 75 can be made of the same materials or different materials. Forexample, the arm 20 or 70 can be made of rigid plastic, the cross bar 30or 73 can be made of silicone, and the pad 32 or 75 can be a gel or foammaterial. It is contemplated that these components can be made of any ofthe group of materials that includes silicon, rigid plastic, gel, foamand the like as known to one of skill in the art. Two slots (not shown)can be defined proximate the arm 20 or 70 for receiving headgear upperfastening straps. Alternatively, slots 22 or 71 can be defined onterminating ends of cross bar 30 or 70 for receiving upper headgearfastening straps (not shown). Mask shell 12, 72 or 92 can includeconnection points 24, 64 or 86 or slots for receiving lower headgearfastening straps (not shown) or quick-release buckles (not shown). Thenumber and location of headgear connection points and slots can varyaccording to desired comfort or stability.

Mask shell 12, 72 or 92, coupling tube 16, 76 or 96, arm 20 or 70 andconnection points 24, 64 or 86 can all be formed of a plastic, forexample, by conventional molding processes, as is known to one havingordinary skill in the art. In at least one exemplary embodiment, maskshell 12, 72 or 92, arm 20 or 70 and connection points 24, 64 or 86 canbe formed integrally by conventional molding processes, as is known toone having ordinary skill in the art. Alternatively, arm 20 or 70 can betwo or more pieces for providing an adjustable arm, as is also known toone having ordinary skill in the art.

The components of cushion 10, 40, 50, 60 or 90 can be formed integrallyby conventional molding processes. Cushion 10, 40, 50, 60 or 90 can bemore flexible than mask shell 12, 72 or 92. Cushion 10, 40, 50, 60 or 90can also be resilient. For example, cushion 10, 40, 50, 60 or 90 (andthe components thereof) can be formed from an elastomeric material, suchas a silicone elastomer. Moreover, inner membrane 3, 43 or 53 can bemade of various flexible materials, such as silicone elastomers, gels,foams and the like known to one having ordinary skill in the art.

Outer sealing membrane 2, 42, 52, 62 or 82 and inner membrane 3, 43 or53 can be substantially triangularly-shaped in whole; similar to frame 1or 61 from which they can both extend. Nevertheless, outer sealingmembrane 2, 42, 52, 62 or 82 and inner membrane 3, 43 or 53 may havenotches and cut-out regions. A membrane can have cut-outs in one or moreregions and may still be deemed substantially triangularly-shaped evenif the three-side shape is incomplete.

Now referring to FIGS. 2-4, where a cross-sectional view of a portion ofdouble-membrane cushion 10, 40 and 50 is shown. Outer sealing membrane2, 42 and 52 and inner membrane 3, 43 and 53 can extend from a firstside of the wall of frame 1, 41 or 51. Outer sealing membrane 2, 42 or52 can be thinner and thus more flexible than inner membrane 3, 43 or53. In at least one exemplary embodiment where the cushion is formedfrom an elastomer such as silicone, outer sealing membrane 2, 42 or 52can have a thickness of between about 0.20 mm and 0.50 mm. Innermembrane 3, 43 or 53 can have a thickness of between about 1.0 mm and2.0 mm. Frame 1, 41 or 51 can be about as thick or can have a greaterthickness than the combined thicknesses of outer membrane 2, 42 or 52and inner membrane 3, 43 or 53 at the thickest point of frame 1, 41 or51.

The second side (cushion mating edge) 4, 44 or 54 of the wall of frame1, 41 or 51 can be directed towards mating geometry with mask shell 12,72 or 92. For example, cushion mating edge 4, 44 or 54 can have a groove(not shown) defined substantially in the middle thereof adapted toreceive a ridge (not shown) formed on mask mating edge 13, 63 or 93.

Outer sealing membrane 2, 42 or 52 can be inwardly oriented. Forexample, outer sealing membrane 2, 42 or 52 can extend from frame 1, 41or 51 and be curved inwardly where outer membrane edge 5, 45 or 55generally defines an opening to central passageway 18, 48 or 58 withinmask 8, 68 or 88 for receiving a user's nose and/or mouth. Outermembrane edge 5, 45, or 55 is located at the terminating end of outersealing membrane 2, 42, and 52. Alternatively, outer sealing membrane 2,42 or 52 can be inwardly oriented without curvature (not shown) and maybe formed in various shapes. For example, outer sealing membrane 2, 42or 52 can be angular in construction (not shown). The portion of theouter sealing membrane 2, 42, or 52 where it immediately extends fromframe 1, 41, or 51 is known as the lower portion of the outer sealingmembrane.

Outer membrane edge 5, 45 or 55 can be adjacent a user's nose or mouthand may contact portions of a user's nose or mouth. In at least oneexemplary embodiment, outer sealing membrane 2, 42 or 52 can have asealing portion for contacting portions of a user's nose that cangenerally run from (or be within) edge 5, 45 or 55 up to portions ofouter membrane 2, 42 or 52 that overlap the outwardly oriented portionof inner membrane 3, 43 or 53. The remainder (non-sealing portions) ofsealing membrane 2, 42 or 52 can face the atmosphere outside of cushion10, 40 or 50.

Inner membrane 3, 43 or 53 can be outwardly oriented as compared toouter sealing membrane 2, 42 or 52, which can be inwardly oriented.Inner membrane 3, 43 or 53 can extend from frame 1, 41 or 51 and can becurved outwardly until inner membrane edge 331, 431, or 531. Innermembrane edge 331, 431, or 531 is located at the terminating end ofinner membrane 3, 43, or 53. Alternatively, inner membrane 3, 43 or 53can be outwardly oriented without curvature (not shown) and may beformed in various shapes. For example, inner membrane 3, 43 or 53 can beangular in construction (not shown). The portion of the inner membrane3, 43, or 53 where it immediately extends from frame 1, 41, or 51 isknown as the lower portion of the inner membrane. Likewise, the portionof frame 1, 41, or 51 where inner membrane 3, 43, or 53 immediatelyextends from is known as the upper portion of the frame. This upperportion of the frame 1, 41, or 51 can have an inner frame surface 111,411, or 511 and an outer frame surface 112, 412, or 512.

An outwardly oriented membrane forming inner membrane 3, 43 or 53 mayprovide one or more benefits over conventional double-membrane cushionsas will be appreciated by one having ordinary skill in the art.Particularly, an outwardly oriented inner membrane 3, 43 or 53 mayprovide increased support and comfort as compared to at least someconventional double-membrane cushion known to those having ordinaryskill in the art.

Outer sealing membrane 2, 42 or 52 and inner membrane 3, 43 or 53 can bespaced (variably or constantly) from each other in each cross-section,as well as between cross-sections of cushion 10, 40 or 50. Particularly,the inner surface of outer sealing membrane 2, 42 or 52 and the outersurface of inner membrane 3, 43 or 53 can be facing each other and canbe spaced. Since, in at least one exemplary embodiment, portions ofinner membrane 3, 43 or 53 may be notched or cut-out, inner membrane 3,43 or 53 would appear abridged (e.g., missing the outwardly curvedportion) or wholly missing, respectively, in cross-section at suchportions. Moreover, outer sealing membrane 2, 42 or 52 and innermembrane 3, 43 or 53 can be contoured in a variety of ways. For example,outer sealing membrane 2, 42 or 52 and inner membrane 3 can bedifferently contoured so as to be variable spaced when comparingcross-sections taken from different portions of cushion 10, 40 or 50.Further, contouring of, for instance, outer sealing membrane 2, 42 or 52may create differing lengths for outer sealing membrane 2, 42 or 52 asmeasured from the extension point at the intersection of membrane 2, 42or 52 and frame 1, 41 or 51 to edge 5, 45 or 55. Thus, edge 5, 45 or 55can be positioned further and, conversely, retracted when comparingcross-sections taken from different portions of cushion 10, 40 or 50.

When properly fitted on a user, a user's nose can be received inbreathing chamber 18, 48 or 58 where the majority of a user's nose ormouth may enter past outer membrane edge 5, 45 or 55 defining the entryaperture of breathing chamber 18, 48 or 58. Portions (i.e., the sealingportion) of outer sealing membrane 2, 42 or 52 can contact areasproximate a user's nose, including proximate the bridge of the nose,around the cheeks, and proximate the skin between the upper lip and thebase of the nose.

Depending on the tension applied to fastening straps of a headgear, itcan be expected that outer sealing membrane 2, 42 or 52 and innermembrane 3, 43 or 53 will remained spaced while an effective seal canstill be provided proximate the nose of a user. The seal may not bedependent on the provision of positive pressurized gas to breathingchamber 18, 48 or 58. Nevertheless, pressurized gas may aid instrengthening or maintaining the seal formed by outer sealing membrane2, 42 or 52.

If nasal mask 8, 68 or 88 is pressed sufficiently tight to a user's faceproximate the user's nose, such as by tensioning of fastening straps,outer sealing membrane 2, 42 or 52 can be expected to deform intocontact with inner membrane 3, 43 or 53. Inner membrane 3, 43 or 53 canthus act as a stopper to hinder further deformation of outer sealingmembrane 2, 42 or 52. Particularly, the opposing orientations of outersealing membrane 2, 42 or 52 and outwardly oriented inner membrane 3, 43or 53 can aid in providing stopper functionality while maintainingcomfort. Without being bound by theory, outwardly oriented innermembrane 3, 43 or 53 can trap gas forming a gas pocket that may propinner membrane 3, 43 or 53, which may assist in providing stopperfunctionality.

Also, without being bound by theory, the outward orientation of innermembrane 3, 43 or 53 can provide stopper functionality withoutunnecessarily interfering with portions of outer sealing membrane 2, 42or 52 proximate edge 5, 45 or 55. Such decreased interference mayprovide greater freedom of movement to outer sealing membrane 2, 42 or52 that may maintain a space between outer membrane 2, 42 or 52 andinner membrane 3, 43 or 53 under somewhat increased tensioning force atleast at certain portions of cushion 10, 40 or 50. Comfort may bemaintained due to spacing between outer membrane 2, 42 or 52 and innermembrane 3, 43 or 53 even if nasal mask 8 is pressed more tightly thanwhat may otherwise be considered optimal.

Indeed, users can apply excess pressure to nasal mask 8, 68 or 88 whenself-fitting even if less pressure would suffice (and be optimal) forvarious reasons, including lack of familiarity with such ventilationinterfaces or simple fear of leakage. For instance, fear of leakage maylead a user to take measures that may sacrifice comfort for illusorysecurity.

Inner membrane 3 or 43 can be outwardly curved so that it may begin tocurve back on itself. In at least one exemplary embodiment, only aportion of inner membrane 3 or 43 can be curved so as to begin to curveback on itself. Nevertheless, in another exemplary embodiment, innermembrane 3 or 43 can be outwardly curved so that it may curve back onitself substantially. Further, in at least one exemplary embodiment,inner membrane 3, 43 can be curved back into a full loop 53 incross-section and can be a hollow tubular structure in whole, as shownin FIG. 4. Alternatively, inner membrane 3, 43 or 53 can be a solidtubular structure lacking a channel defined through the center. In suchembodiments, the solid construction can provide additional stopperfunctionality as opposed to an air pocket.

Comparing cushion 10, 40 and 50 FIGS. 2-4, outer sealing membrane 2, 42or 52 can extend from frame 1, 41 or 51 in a variety of ways. Forexample, outer sealing membrane need not have a substantial outwardprotrusion upon extending from frame 1, 41 or 51. Also, inner membrane3, 43 or 53 can protrude inwardly before being oriented outwardly.Numerous other configurations will be readily recognized by one havingordinary skill in the art having the benefit of this disclosure.

In another exemplary embodiment in reference to full masks as shown inFIG. 5, particularly full masks 68 having a general triangular portionadapted to mate (with or without additional mounting components) with aface cushion 60 having a substantially triangular-shaped frame 61. Theface cushion can be a double-membrane cushion 60 having an outwardlyoriented inner membrane.

In yet another exemplary embodiment in reference to oral masks orportions of hybrid masks 88 (i.e. those masks having an oral cavity andeither nasal inserts or nasal prongs) as shown in FIG. 6 having ageneral oval portion 93 adapted to mate (with or without additionalmounting components) with a face cushion 90 having a substantially ovalframe 81. The oral cushion can be a double-membrane cushion 90 having anoutwardly oriented inner membrane.

The foregoing description and accompanying drawings illustrate theprinciples, preferred embodiments and modes of operation of theinvention. However, the invention should not be construed as beinglimited to the particular embodiments discussed above. Additionalvariations of the embodiments discussed above will be appreciated bythose skilled in the art.

Therefore, the above-described embodiments should be regarded asillustrative rather than restrictive. Accordingly, it should beappreciated that variations to those embodiments can be made by thoseskilled in the art without departing from the scope of the invention asdefined by the following claims.

1. A ventilation interface comprising: a cushion; the cushion including:a central passageway; an outer sealing membrane; and an inner membrane,wherein the outer sealing membrane has a first terminating end thatextends towards the central passageway, wherein the inner membrane has asecond terminating end that extends away from the central passageway. 2.The ventilation interface of claim 1, wherein one of the outer sealingmembrane and the inner membrane extends from a cushion frame.
 3. Theventilation interface of claim 1, wherein the outer sealing membrane andthe inner membrane are integral.
 4. The ventilation interface of claim1, wherein the outer sealing membrane and the inner membrane areseparate.
 5. The ventilation interface of claim 1, wherein one of theouter sealing membrane and the inner membrane is made of a flexiblematerial.
 6. The ventilation interface of claim 1, wherein the innermembrane consists of gel.
 7. The ventilation interface of claim 1,wherein the inner membrane consists of foam.
 8. The ventilationinterface of claim 2, wherein the second terminating end of the innermembrane extends beyond an upper portion of an outer surface of theframe.
 9. The ventilation interface of claim 2, wherein the secondterminating end of the inner membrane does not extend beyond an upperportion of an inner surface of the frame.
 10. The ventilation interfaceof claim 1, wherein the inner membrane has at least one notch.
 11. Theventilation interface of claim 2, wherein the second terminating end ofthe inner membrane overlaps a lower portion of the inner membrane in adirection parallel to the upper portion of the inner surface of theframe.
 12. The ventilation interface of claim 1, wherein the innermembrane curves in a different direction than the outer sealingmembrane.
 13. The ventilation interface of claim 1, wherein the innermembrane and the outer sealing member are configured to maintain adistance during use.
 14. The ventilation interface of claim 1, whereinthe outer sealing membrane has a lower portion that extends away fromthe central passageway.
 15. The ventilation interface of claim 1,wherein the inner membrane has a lower portion that extends towards fromthe central passageway.
 16. The ventilation interface of claim 1,wherein the inner membrane is configured to trap gas during use.
 17. Theventilation interface of claim 1, wherein the outer sealing membrane hasa first thickness and the inner membrane has a second thickness; andwherein the second thickness of the inner membrane is greater than thefirst thickness of the outer sealing membrane.
 18. A cushion comprising:a central passageway; an outer sealing membrane; and an inner membrane,wherein the outer sealing membrane has a first terminating end thatextends towards the central passageway, wherein the inner membrane has asecond terminating end that extends away from the central passageway.19. The cushion of claim 18, wherein the second terminating end of theinner membrane extends beyond an upper portion of an outer surface of acushion frame.
 20. The cushion of claim 18, wherein the secondterminating end of the inner membrane does not extend beyond an upperportion of an inner surface of a cushion frame.
 21. The cushion of claim18, wherein the outer sealing membrane has a first thickness and theinner membrane has a second thickness; and wherein the second thicknessof the inner membrane is greater than the first thickness of the outersealing membrane.
 22. The cushion of claim 18, wherein the innermembrane curves in a different direction than the outer sealingmembrane.
 23. A ventilation mask comprising: a shell; the shellincluding a gas entry port; a cushion interface; the cushion interfaceincluding: a central passageway; a first membrane; and second membrane,wherein cushion interface is coupled to the shell, wherein the firstmembrane has a first terminating end that extends towards the centralpassageway, wherein the second membrane has a second terminating endthat extends away from the central passageway.
 24. The ventilationinterface of claim 23, wherein the first membrane has a first thicknessand the second membrane has a second thickness; and wherein the firstthickness and the second thickness are different.